The sportsman and actor - famously acquitted for the 1994 murder of ex-wife Nicole Brown - said nobody discussed using guns before he and a group of men entered the hotel room to claim the belongings back.

"There was no talk about guns at all," said Simpson.

Simpson is serving nine to 33 years in a Nevada state penitentiary, after being convicted in October 2008 over the Las Vegas robbery, which was infamously caught on security camera footage.

He is seeking a retrial on grounds that his longtime lawyer Yale Galanter had botched his defence.

In a 94-page petition, Simpson alleges Mr Galanter knew of his intention to recover personal items which he was ultimately convicted of trying to steal at gunpoint from two memorabilia dealers at the Sands Station hotel.

He also claims that Mr Galanter did not tell him about a plea bargain offer that might have resulted in a substantially shorter period behind bars.

Mr Galanter is due to testify on Friday.

Simpson was convicted in the Las Vegas case 13 years to the day after his acquittal in the murder of Ms Brown and her friend Ronald Goldman.